In general, in plastic working of metal materials, for the purpose of preventing from seizure and galling caused by metal contact between materials to be worked and tools, coatings that have lubricity are provided on the metal material surfaces. Such coatings include a reactive type of forming, on a metal material surface, a chemical conversion coating by chemical reaction, and then further forming a lubricating coating. For example, widely used are lubricating coatings that have a two-layer structure obtained by forming, on a metal material surface, a chemical conversion coating such as a phosphate coating (target metal: iron and steel, magnesium, and the like), an oxalate coating (target metal: iron and steel, stainless steel, and the like), or an aluminum fluoride coating (target metal: aluminum) that has a role as a carrier, and then further applying a lubricant such as a lime soap, a molybdenum disulfide, or an oil, and lubricating coatings that have a three-layer structure (chemical conversion coating/metal soap coating/unreacted soap coating) obtained by applying a chemical conversion coating, and then coating with a reactive soap such as sodium stearate. In particular, the latter lubricating coatings that have the three-layer structure are known to be capable of producing stable and excellent lubricity even in heavy working regions.
However, the chemical conversion treatment with the chemical reaction and the reactive soap require solution management, temperature management for controlling the chemical reaction, removal and disposal of sludge as a reaction by-product, and disposal renewal due to solution deterioration. For the purpose of global environmental conservation in recent years, the reduction of industrial waste has become a great problem. To that end, lubricating coating agents and treatment methods which produce no waste have been desired.
Furthermore, lubrication treatment methods provided with chemical conversion treatment steps have required a long treatment process as follows, and a lubrication treatment which has a short treatment process, and allows a short time treatment has been thus desired conventionally.
acid cleaning→first water rinsing→second water rinsing→chemical conversion treatment→first water rinsing→second water rinsing→lubrication treatment
In response to the requests mentioned previously, lubricants are cited which can carry out a chemical conversion treatment and a lubrication treatment at the same time. For example, Patent Literature 1 discloses an acid lubricant containing, as its main constituents, 0.1 to 30 weight % of a water-soluble and/or water-dispersible resin, and one of emulsified and dispersed paraffins, waxes, esters of higher fatty acids, and metal soaps, or a mixture thereof in a phosphoric acid aqueous solution with a concentration of 1 to 50 weight %.